Vent for cleaning systems



Dec, l0, H935. J. MAHONEY VENT FOR CLEANING SYSTEMS Filed Dec. 13, 1954 M R wf o M mw E WW .VMT IM HNA M mi. o J I' YW ORNE Y! Patented Dec. 10, 1935 UNED S'ATE l-)ATENT OFFICE VENT FOR CLEANING SYSTEMS Application December 13, 1934, Serial No. 757,412

Claims. l(Cl. 261-7) My invention relates to vents and more particularly to liquid seal vents for vessels, tanks or systems in which a volatile liquid or solvent is stored or utilized.

In fabric treating apparatus it is desirable in economical operation to repeatedly utilize the same supply of detergent and to have the detergent equally effective in each operation. In such apparatus means are therefore provided to remove the foreign matter, such as grease and dirt, from the detergent after the treating operation. To prevent the loss of solvent and its contact with moisture in the air, it is also desirable to have the vessel or system as nearly closed to the atmosphere as possible. This is particularly important in treating vessels or systems in which the detergent is carbon tetrachloride, which, especially when hot, reacts with water to form hydrochloric acid which materially weakens the fabric and may even attack the metal parts of the vessel or apparatus in which the fabric is being treated. To avoid the necessity of constructing the vessel or system of excessively strong material and to obviate the possibility of injury to the apparatus or system as the result of abnormal vacuum or pressure conditions, means are preferably provided to permit sufficient vent to the atmosphere to prevent the formation of abnormal vacuum or pressure conditions within the apparatus or system.

It is therefore an object of my invention to provide an improved liquid seal vent for tanks or systems in which a volatile solvent is stored or utilized. Another object of my invention is to provide a liquid seal for tanks, vessels or cleansing systems by means of which air containing the volatile solvent vapors may escape to the atmosphere and the solvent may be condensed and automatically returned to the tank or system. A further object of my invention is to provide a liquid seal vent for cleansing systems in which carbon tetrachloride is utilized as the solvent, by means of which air may be vented to the atmosphere when abnormal pressure conditions exist within the apparatus or system and the condensed solvent may be automatically returned to the vessel or system.

My invention will be better understood by reference to the accompanying drawing in which Fig. 1 is an elevation illustrating my improved vent as applied to a dry cleaning apparatus; and

Fig. 2 is a similar view, showing a modified form of vent.

The invention is particularly designed for use in conjunction with cleansing systems in which a volatile solvent, such as carbon tetrachloride, is utilized as the cleansing medium and constitutes an improvement of the vent disclosed in the copending application of Russell A. Hetzer, Ser. No. 658,577, filed February 25, 1933, which has since 5- matured into Patent No. 1,995,065 dated March 19, 1935, to which reference may be had if desirable or necessary.

As illustrated in the drawing, the fabric cleansing system comprises a treating vessel I which is provided within its tub with the usual rotatable work containing drum. A storage tank 2 is mounted at a higher level thanV the treating vessel I and, as illustrated, contains a supply of Volatile liquid to be utilized in the treating operation. Carbon tetrachloride is preferably utilized as the volatile detergent although other volatile detergents may be employed. The conduit or pipe 3 connects the bottom of the storage tank 2Y with the treating compartment I and' is provided with 20 a valve 4 for regulating the amount of treating medium which passes from theV storage. tank to the treating compartment.

In order to prevent any water or moisture which may collect and float on the surface of the treating medium within the storage tank 2. from gravitating into the treating compartment I through the conduit 3, the portion of the conduit 3 within the tank 2 is provided with two branches 5 and 6. The branch 6 extends upwardly to a point above 30 the level of the treating medium within the storage tank, and the branch 5 is in the form of a 90 elbow having its lower open end but slightly above the bottom of the tank 2. The solvent which is supplied to the treating vessel through the conduit 3 will therefore always flow from thev lowermost part of the storage tank. When valve 4 is open for supplying solvent to the treating compartment I, the treating medium will drain from the storage tank 2 until it has reached a level 40V treating compartment.

A drain conduit 'l provided with valve 9 leads from the bottom of the treating compartment I 50, to a sump tank 3' located below the compartment. Filter means I0 are provided at the delivery end of the conduit 'i for separating particles of .foreign matter. Y

lIn renovating the used treating medium, it is 55.

first drawn from the sump tank 8 through a conduit I I, under the control of a valve I2, by

means of a pump I3, and is forced into an evaporator I4. The solvent is then vaporized, the

Vvapors being passed to a condenser I5 by way Vof a conduit I6.

'Ihe condenser I5 is provided with conduits I5a for passing a suitable cooling medium, through the condenser. The condensed liquid or treating medium is then delivered to a point adjacent -the bottom of the storage tank 2 by way of a conduit I1 and a filter I8. An'auxiliary evaporator I9, having operative connectionA with the evaporator I4 and condenser` I5, is provided to operate in conjunction with'the eVap-- orator I4. Any treating medium not vaporized in the evaporator I4 and the treating Vmedium remaining in the sludge that Vdeposits in the bottom of the evaporator I4 may thus be recovered. Y In addition to the app-aratus for recirculating and Yrenovating the treating medium, suitable means are provided for 'drying and deo'dorizing the fabric in the treating compartment beforeV removal of the fabric; This apparatuscomprises a condenser 2D provided with a coolingrcoil 20a, afan 2| and an air'heater 22 providedVV with a steam coil 22a, all connected in a circuit 'withl the.treating'compartment I. The circuit is provided with suitable valves 23, 24 and 25. YWhen valves 23 and 25 are closed and valve 24 is open,

heated air may be repeatedly passed through the treating compartmentrin a closed circuit to dry the'fabric and whenvalves 23 and 25 are open and valve 24 is closed, atmospheric air may be drawn into the treating compartment ,andY discharged to the atmosphere to deodorize the fabric, the condenser 2D serving to reclaim any treating medium carried away from the Vfabric by the circulation of air therethrough. y

In accordance with my invention, an improved vent isY provided'for relieving abnormal pres-Vl sure conditions existing within the vesselorsystem by means of which the air, laden with sol-V vent vapors which otherwise would escapeffrom the apparatus, is subjected to a washing process tank or receptacle 26 contains a liquid 2'IWhicrh has less specific gravity'and is substantially in- -soluble in the volatile solvent, or a liquid in which theY volatile .solvent'utilized will stratify as a lower layer. For instance, water may be utilized as thewashing medium when carbon Ytetrachloride is utilized as the treating 'solventin thevessel or system.. Other liquids Yof the type specified maybe of course employed, such as methyl orV ethyl alcohol, although I prefer to utilizewater-.because it is inexpensive and non-inflammable. Y Y Y Y l VVIn the vent pipe arrangemenaaconduit 23,

always open, extends kfrom a position belowlthe minimumlevel of liquid which is always maintainedin the sump'tank 8, to the interiorof the tank or receptacle YZES. i The conduit 28 terminates Vin a T-connection, one end 30 of which, extends toga point above the liquid in Vthe receptacleor tank 26 and the otherjend `3I'1oiY which ex' tends toa-.point justabove` theV bottom of the leferitacle4 or tank. VA conduitf32 ledsrfmm'the' '35 and no further liquid flows.

Y means'for indicating the level of combined liquid Vupwardly through the condenser 23 into the con- Y' ment I to equalize the'vacuum condition rwhich condenser 20 to the top of the sump tank 8 by way of a conduit 33, and a conduit 34 having ay Y check valve'35 therein leads from kthe joinder off the conduits 32V and 33 to a point adjacent the bottom of the tank or receptacle 26. This conduit 5, V34 has a connection with the storage tank 2 by." way of a conduit 36. Suitable vacuum breakersl 37 and 38 are provided in this system of vent conduits for relieving vacuum conditions within any part of the apparatus. A conduit 39 leads from the top of the tank or receptacle 25 j to the atmosphere.

In the operation of this part of the apparatus, as the solvent indicated by the numeral 40 accumulates in the tank or receptacle 26 due to the condensing action, the combined level of the washing liquidrand solvent tends to rise above the point at which the conduit 28 connects with the T-connection within the tank or receptacle. When the level of the combined liquid and solvent rises to a suiiicient extent above the T- connection, the solvent 40 iiowsout of the receptacle from the lower end 3| of the branch into the conduit 28, and thence into theV sump tank 8, under pressure of the head of liquid in the 25 receptacle 26 until the level of solvent in the verticalV portion of the T-connecton drops below the point at which the conduit'28 communicates therewith.' The Siphon effect is then broken by the admission of air through the open branch 30 The head of washing liquid inthe receptacle 26 is just enough to maintain a given amountof solvent 40 within the receptacle and to prevent removal of anything but the solvent 40 or treating medium. 35

Becauseof the importance of maintaining a given amount of lwashing liquid 2I in the receptacle, it may be Vprovided with a sight glass 21a or other and treating medium. 40 The operation of my improved vent as applied to a cleansing Vsystem will now be apparent. When the treating medium or solvent for a washing operation is admitted tothe treating cornpartment I from the storage tank 2, the air which 45 this treating medium or solvent displaces in the treating compartment I has become vapor laden and some of this vapor, which will not all be condensed in the condenser 29, passes with the air duit 32 pastcheck valve 35 through conduit'36 into the storage tank 2, thus equalizing the pressure in the storage tank. Should a`condition exist where the pressure in the conduitsr 32, 34 and 36 is greater than is required to equalize pressure 55 in the storage tank 2, the additional vapor laden air will be conducted to the receptacle 25 where it willbubble up through the liquid 21 and the vapor containedy therein will'be condensed and collect at thevbottom in the form of the pure sol 60 vent 4I). The air will pass out at the top of the receptacle through conduit 39 to the atmosphere. Similarly, when the treating medium is drained from the Vtreatingcompartment I into the sump tank, it displaces a'quantity of air in the sump 05 tank,which is saturatedwith solvent vapor, and which passes upwardly through the conduit 33 through the conduitYV 32 into the condenser 2E! thence downwardly into the treating compart-y was affected by the draining of the solvent. As inthe'former case,rshould an excess pressure condition exist, that excess pressure is relieved by passage of the vapor laden air through thegconduit 34 -past Ythe check valve 35 Aandfintothere- 75 ceptacle 25, where the solvent vapors are removed by the liquid 2l and the free air passes to the atmosphere.

When the treating solvent is pumped from the sump tank to the evaporator i4 Vfor the purpose of renovation, a quantity of air which is vapor laden due to its contact with the solvent and part of which is non-condensable in the condenser I5, passes upwardly to the conduit i6, through the condenser 5, downwardly through the conduit l1 into the storage tank 2 and thence bubbles up through the contents of the storage tank. In order to relieve abnormal pressure conditions in the storage tank this air laden with solvent vapors is passed through conduits 36 and 34 into the receptacle 26 where the vapor is removed by the liquid 21 and the free air passes into the atmosphere. The passage of the vapor laden air from the conduit 35 toward the conduit 32 is prevented by the check valve 35.

During the renovation process, the hot vapor passes from the evaporator i4 into the condenser l where the vapors are condensed and the puried solvent drains into the storage tank 2. The vapor laden air which is displaced in the storage tank 2 passes upwardly through the conduit 3B, thence through conduit 34 to the receptacle 26, where the vapors are removed and the free air passes to the atmosphere. Again, in this case, the vapor laden air from the conduit 36 is prevented from passing into the conduit 32 by the check valve 35.

Referring to Fig. 2, I have shown the modified form of my invention wherein the washing apparatus hereinbefore described is provided with a spray device or atomizer for delivering the air washing liquid at the top of the tank or receptacle 25. In this arrangement, a conduit 4i is connected to the tank or receptacle 26 and extends into the liquid 21, the point of entrance of the conduit being at such a height that it will at no time be in connection with the solvent 40. The other end of the conduit 4| is connected to a pump 42 and another conduit 43 leads from the pump 42 to the top of the tank or receptacle 26 where it extends into the space above the liquid 2l' and is joined to a spray device or atomizer 44. Otherwise the air washing apparatus is the saine as that hereinbefore described.

The construction of the drain pipe for removing solvent from the receptacle 26 is particularly important where the spray device or atomizer forms a part of the apparatus. For example, the arrangement of the drain with the end of the T-connection terminating below the spray head 44 will insure that a space will be provided between the liquid level and the head 44 in which a spray of condensing liquid may be effectively maintained.

While in Fig. 2 the pipes 23, 39 and particularly those portions of said pipes which are within the vessel 26, are shown as separate pipes, it is obvious that from the physical standpoint they can actually be parts of the same continuous piece of pipe, with an opening through the wall of said pipe to the gas space above the liquid within vessel 26, as shown in Fig. 1, all as. will be readily understood.

From the foregoing speoication it will be apparent that I have provided an improved liquid seal vent by means of which abnormal pressure conditions within a vessel o-r system may be relieved and whereby the volatile solvent may be condensed and returned to the vessel or system.

It will also be seen that my improved vent is automatic in operation and may be so constructed that only comparatively pure solvent will be returned to the system. This is very important because if water is employed as the washing medium it is essential that the water should be kept out of the system. K

To those skilled in the art many modiications of and widely different embodiments and applications of my invention will suggest themselves Without departing from the spirit and scope thereof. My disclosure and description are purely illustrative and are not to be in any sense limiti'ng.

What I claim is:

1. A liquid seal vent for tanks or systems in which a volatile solvent is stored or utilized, comprising a receptacle containing a condensing liquid having a lower specific gravity than the volatile solvent and from which the volatile solvent will stratify, a vent from the upper portion of sai-d receptacle, a conduit leading from the tank or system and terminating below the condensing liquid in the receptacle, whereby volatile solvent vapors escaping from said tank or system will be condensed and will settle below the condensing liquid in the receptacle, and means for automatically returning condensed liquid back to the tank or system after a predetermined amount has collected in said receptacle.

2. A liquid seal for tanks or systems in which a volatile solvent is being stored or utilized comprising a receptacle containing a condensing liquid having a lower specific gravity and in which the volatile solvent is not more than slightly soluble, a vent in the upper portion of said receptacle and a conduit leading from the tank or system and termin-ating below said liquid, whereby volatile solvent vapors escaping from the tank or system will be condensed and will settle beneaththe liquid in the receptacle and the air will escape to the atmosphere, automatic means for conducting solvent back to said tank or system when a predetermined amount has collected in said receptacle, .and automatic means for terminating the iiow when the solvent has fallen to a predetermined level.

3. A liquid seal for tanks or systems in which a volatile solvent is stored or utilized comprising a receptacle containing a condensing liquid having -a lower specific gravity than the solvent and in which the volatile solvent is not more than slightly soluble, a vent in the upper portion of said receptacle and a conduit leading from the tank or system and terminating below the condensing liquid in the receptacle, whereby volatile solvent vapors escaping from said tank or system will 4be condensed and will form a layer below the condensing liquid and the air will pass to the atmosphere, and means for automatically returning the solvent back to the tank or system comprising an open conduit extending from below the liquid in the tank or system having a vertical connection extending vertically in said receptacle, one end of which terminates near the bottom of the receptacle and the other end of which terminates above the condensing liquid in said receptacle.

4. A liquid seal for tanks or systems in which .carbon tetrachloride is being stored or utilized comprising a receptacle containing water, a vent leading from the upper portion of said receptacle, a conduit leading from the tank or system and terminating below the Vwater in the receptacle, whereby when excess pressure exists in said tank or system air containing carbon tetrachloride may escape from the tank'or system through Y the water inthe receptacle and the carbon tetrachloride vapors will be condensed and will settle below the water, and meansfor automatically returningY the condensedY carbon tetrachloride back toY the tank or system after a predetermined amount has collectedin said receptacle.

5. A liquid seal for tanks or systems in which carbon tetrachloride is being stored orutilized comprising a receptacle containing water, a vent in theupper portion of said receptacle and a conduit leading from the tank or system and terminating below the water in therreceptacle, 

